1. Field of the Invention
The present invention relates to an artificial spine, more particularly, an artificial spine for use in a vertebral canal expansion operation. After a spine including a vertebral arch of the cervical spine is longitudinally divided in its middle line into two parts, the artificial spine is inserted into and fixed between the divided parts of the spine.
2. Description of the Related Art
Hitherto, to remove defects caused due to the pressurizing of a spinal cord in a spondylotic myelopathy and an ossification of posterior longitudinal ligament of the cervical spine, a vertebral canal expansion operation has been carried out, and particularly a spinal longitudinal separation has been frequently carried out and now is an established operation method. In the prior art of spinal longitudinal separation, a fragmental bone is separated from an ilium, and is inserted and fixed between the longitudinally divided spines, however, such separation of the ilium is a hard on the patient.
Recently, an artificial spine of the ceramic material has been used in place of the fragmental iliac bone. However, artificial spines of the ceramic material of the prior art have a configuration which does not conform with the actual shape of the divided spines very well, and therefore they can not be fitted with a good compatibility to a gap formed between the divided spines. As a result, there arises problems of bone resorption being generated and that the adjacent artificial spines can be contacted with each other, thereby inhibiting a movement of the cervical spine.